An action to enjoin a “public nuisance” – i.e. activity that impairs the safety or health of a community – is a primary land use litigation tool which local governments use to enforce local bans against supply-side operations in the cannabis market. The question that is being litigated is whether state laws permitting medical use of cannabis “preempt,” i.e. “override,” local laws, leaving the local governments unable to ban something permitted by a higher level of law. This issue will be tested in each state that enacts laws permitting some form of a legal cannabis market to whatever degree – probably many times in each state as multiple cases from lower level courts begin heading to the appellate courts, as is happening in California.